Process of dehydrating animal and vegetable substances.



PATENTED NOV. 26, 1907.

E. W. OOOKE. PROCESS OF DEHYDRATING ANIMAL AND VEGETABLE SUBSTANCES.

APPLICATION FILED DEO.21, 1906.

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UNITED STATES ATENT OFFICE,

ERNEST -W. COOKE, OF WAUKESHA, WISCONSIN, ASSIGNOR, BY MESNE ASSIGNMENTS, TO AMERICAN DEHYDRATING COMPANY, A CORPORATION OF WISCONSIN.

PROCESS OF DEHYDRATING ANIMAL AND VEGETABLE SUBSTANCES.

' Specification of Letters Patent.

Application filed December 21. 1906. Serial No. 348.968.

Patented Nov. 26, 1907.

To all whom it may concem:

Be it known that I, ERNEsT W. CooKE, a citizen of the United States, residing at Waukesha, in the county of Waukesha and State of Wisconsin, have invented certain new and useful Improvements in Process of Dehydrating Animal and Vegetable Substances, of which the following is a specification.

My invention relates to a process of dehydrating material, which is especially adapted to the dehydration of food substances, both animal and vegetable; I a

The object of my invention is to provide an improved process for the purpose stated, whereby the material treated Will be perfectly dehydrated Without losing any of its essential constituents or characteristics, and so that it can be restored to its original condition by the mere addition of water. M -I have heretofore found that, when dried air is passed through material of the kind mentioned, a certain proportion of the volatile oils are frequently carried off by the air, and not merely the water, whereby'the material loses some of its characteristics.

An essential feature of my present invention consists in passing the air in a continuous circuit through the material and condensing out the water only, whereby such volatile constituents, as may have been car-' ried ofi as'well, are returned to and reab sorbed by the material, whereby a greatly means for holding the material therein forms a tunnel, in WhlCll case the ends of the sucim proved dehydrated product is obtained. he process consists in the steps to be hereinafter described in connection with the accompanying drawing, which I have illustrated diagrammaticallyand by way of example only, an arrangement of apparatus by which the process can be carried out.

In the draw1n 1 represents a dehydrating chamber, here s own as consisting of a series of compartments 2, 3, 4, 5, 6 and 7, in

which the material or materials to be treated are laced, preferably on trays arranged in stac s. The construction ofthe dehydrating chamber, as well as of the trays or other nopart ofmy present invention, and they are conse uently not here shown in detail. The dehyd rating chamber may consist of any number of compartments or may be merely cessive stacks of trays constitute partitions which prevent the air used in the process inafter claimed is concerned, whether the trays are moved intermittently through the chamber, or not. With the arrangement of piping and valves shown in the drawing, the chamber is simply loaded up with stacks of trays, which remain stationary during the process and may be removed from the same end at which they were put in, but my process is equally applicable to 'the case where thetrays are intermittently fed through the chamber or tunnel, as will be apparent.

Pipes 8 and 9 are rovided to convey air into and out of each compartment of the chamber and, in the form shown, each of said pipes acts alternately as an inlet ipe and as an outlet pipe, the direction of tie currents ofair being reversed through the sections of the chamber at intervals.

10 and 11 represent air-driers, which may be of any ordinary type, the only essential being that they contain a moisture-absorbing substance,.such as calcium chlorid, for example, supported on trays or otherwise. Each drier is used alternately to heat the air and remove moisture therefrom before it is passed to the dehydrating chamber, and while one of them is thus being used, the other is being dried again in a well-known way, by passin heated air therethrough, the air being heate by the steam-coils 50 and 51 shown in dotted lines. The air which is used to deh drate the food is passed downwardly througli the driers from the pipes 12 and 13,

and issues therefrom through the pi es 14- and 15 into a commonpipe 16 from w 'ch it passes, either directly into the pipe 8, or through the branch ipe 17into the plpe 9, and thence into the chamber, either at the top thereof or at the bottom, as the case may be. The air for drying the moisture-absorbing substance in the drier which is not being use at the time comes through the ipe 18 or the pipe 19 and issues into a stacr 20. When elther drier is in use, the pipe 18 or 19, as the case may be, and the pipe leadin to the stack 20 from that drier, are shut o by the valves 21, and the valves 22, in the Ipipes 12,

14 and 17, which are the pipes Whic convey the air to be passed through the material into pipe 9, the valv 24 in said P is opened;

the valve 22 in the branch pipe 17 is closed while the valve 22 in the plpe 8 is opened and the valve 24 in the branch pipe 25 is closed. The condenser 27 is provided with inlet 28 and outlet 29 for a cooling medium, such as brine or ammonia, and with-outlets 30 for the condensed water, leading to a trap 31, whereby the water can be drawn off without let- 'tin any air into the condenser.

F rom the condenser the air issues through ipe 32, leading to the suction side of the blower 23, thus completing the circuit. A valve 33 is provided in a branch of the pipe 32, through which from time to time, as may be necessary, additional air may be admitted into the circuit to replace such air as may be carried 0 with the water ofcondensation. The operation briefly stated, is as follows: The dehydrating chamber being loaded with material, the blower is started and air is forced through one of the driers 10, 11, into the chamber, passing through the sections thereof either upwardly or downwardly. The other drier is meanwhile being heated preparatory to being usedin its turn. After thus passing through the materlal, the air, carrylng more or less moisture extracted from thematerial, passes into the condenser, 40 .where it is cooled and a part of the moisture condensed. It is impossible to remove in the condenser, as much of the moisture as is necessary for the proper dehydration of. most materials, and, of course, when the air leaves Hence it is passed from there into a drier, either 10 or 11, where its temperature is raised to the desired degree and a further amount of moisture is extracted. It is then passed again through the material, either inthe samedirection or in the opposite direc tion. In practice the flow of the air is constant and the direction of flow throu h the material isreversed at intervals, the ength the material bein treated.

.While I have s cated between the condenser and the driers, it may, of course, be placed at any convenient point in the circuit. It will be a' parent, when one of the driers, 10 for examp e, has become cooled and more or less saturated with moisture extracted from the air flowing through it on its way to the chamber, and consequently the other ing the temperature imparted to the drler is used, might, be

the condenser, it is a very low temperature.

of which depends upon the requirements of 'rangement of own the blower 23 as lodrier '11, which has meanwhile been heated and dried, is switched on, that the temperature of the current of air will be'suddenly raised and that its temperature gradually diminishes from that time until the first drier 10 is switched on again, when the temperature is suddenly raised again, and so on. This is an important feature of my process, because these sudden increases in the temerature of the current of air flowing through the dehydrating chamber cause the material to expand and the moisture to be sucked out, while the subsequent gradual diminutions in the temperature prevent the material from being burned or dried too quickly. These variations in temperature can .be regulated .as required for any particular material by varying the length of time for which each drier is used in the circuit, as well as by vary-.

while it is cut out of the circuit.

Where, as sometimes occurs, the air comm into the drier contains but little more moisture than that required for the treatment of a certain material, it is impossible to raise the temperature of the air to the desired point without extracting too much moisture. Also, when the air entering the drier is of low humidity,'if it were heated in said drier to the tem erature required, some of the calcium 'carbi ,where that substance carried over with the air into the material, which would obviously be undesirable. Under these conditions therefore I make use of the steam-coil in he base of the drier, as a superheater for thc zr,

whereby the desired temperature can bL 1mparted without any detrimental result. I In other words, whereas ordinarily the steamcoil of the drier is shut off while that drief is in the circuit, itis left on under certain conditions in order to still further heat the air after it leaves the drier proper on its way to .the dehydrating chamber.

It will now be seen that my process consists essentially in passing a current of air in a continuous circuit through the material and tem ering its heat and humidity to ary desired egree in that portion of the circuit outside the dehydrating chamber.

It will also be apparent why it is necessary to employ both a condenser and a drier, and, in some cases, also a super-heater.

Finally, it mus't'be understood that the ara paratus shown in the drawing is merely il ustrativeof the process and that many other arrangements could be used equally as well. A

Having thus described my invention, its function and result and the manner in which it is carried out, what I claim is 1. ,The process of dehydrating food substances, which consists inplacing them on l5 through the substances at 1 variable intervals.

5 rection.

2. The process of dehydrating food substances, which consists in placing them on stationary trays in a closed chamber, passing a current of dry air through the same in one 10 direction for a certain period of time, removing the moisture from said air While away from said chamber, returning said air through the same substances again, and reversing the direction of flow of the air predetermined,

3. The rocess of dehydrating food sub stances, which consists in assing a current of dry air upwardly throug the same While in a closed chamber, removingthe moisture from said air while away from said chamber and again passing the same airthrough the substances in the chamber but in the downward direction.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ERNEST W. COOKE. 

